ABSTRACT
Strain relaxed SiGe epitaxial layers were grown on the compositionally graded layers on Si(001) substrates at 730°C, and 900°C by molecular beam epitaxy. We observed etch-pits by scanning electron microscopy and atomic force microscopy after Schimmel-etch with various time. The analyses show that the etch-pits are related to threading dislocations. The Schimmel-etch seems to follow the kinematic wave theory of dissolution and etch-pit formation. Deep level transient spectroscopy exhibits a hole trap in the present sample. The energy and the capture cross section of the hole trap are EH=EV+0.62±0.05 eV and σ H~5.5×10-10 cm2 , respectively. This hole trap is associated with threading dislocations and/or misfit dislocations in compositionally graded layer.
